A Vapi alternative for Hindi and Hinglish phone agents

How do Vapi and Voice Infra differ?

Vapi is an orchestration platform. You choose a transcriber, a language model, a voice and a transport for each assistant, and Vapi runs the conversation between them. Its pricing page says the per-minute cost has four components (speech-to-text, the language model, text-to-speech and transport), each billed at the provider’s listed price with no markup, with Vapi’s $0.05 a minute hosting fee added on top. Bring your own provider keys and that provider bills you directly.

Voice Infra runs one stack, the Mira stack, on every tier. Mira STT and Mira TTS are our own models, and the price covers the whole call: recognition, the model, the voice, and on T5 and T3, the phone line and call insights. The tier changes the price and nothing else. Minutes are metered in 10-second blocks, rounded up, and calls that ring out, hit a busy line or fail to connect are not billed.

Vapi fits when you want to swap providers per assistant or call in many countries. Our stack fits Hindi and Hinglish calls to Indian numbers when you would rather not assemble and pay four vendors.

What does a minute cost on each?

Vapi’s own calculator, at 1,000 minutes a month with its defaults, shows a $50 hosting fee, $10 for Deepgram, $8 to $45 for OpenAI and $15 to $24 for ElevenLabs, a total of $82 to $129. Transport is separate. The pricing page lists Vapi Telephony and SIP as free and Twilio outbound at $0.014 a minute; the carrier you use for Indian numbers sets its own rate.

On Voice Infra, the same 1,000 minutes on T5 is 1,000 × ₹5 = ₹5,000, phone calling and insights included. At volume the rate drops to ₹1 a minute on T1, whose ₹1,00,000 monthly minimum buys 1,00,000 minutes of voice AI; Mirai phone calling (₹0.30 a minute) and insights (₹0.20 a minute) are optional extras there. In between, T3’s ₹50,000 monthly minimum buys 16,666 minutes at ₹3 (₹50,000 ÷ ₹3). Prices exclude GST. The pricing guide shows how to forecast a month with the 10-second rounding.

What does moving a Vapi assistant look like?

Most of an assistant carries over. The system prompt and first message become system_prompt and first_message on POST /v2/agents, and per-call details go in as {{variables}}. You place a call with POST /v2/calls, which returns 202 because the phone has not rung yet, and the outcome reaches you through signed webhooks. Lookups and CRM updates map to tools that run before, during or after the call. If your assistant follows a fixed flow, node-based agents are available on every tier. The quickstart creates a key, an agent, a call and a webhook, and places one real call, in five minutes.

Plan for two gaps on our side: transfer to a person is not available yet, and new workspaces start at 5 concurrent calls until we raise the limit. The webhook guide covers retries and deduplication on our side.

If you are keeping your own orchestration and only want a Hindi voice, you do not have to move the agent at all. Mira TTS speaks OpenAI’s POST /v1/audio/speech protocol, so a client that already calls OpenAI’s speech API needs a new base URL and model name.

What should you test before switching?

Take a few recordings of real Hindi or Hinglish conversations your team has had, with consent, and write test scripts from them: the names, amounts, addresses and English product words your customers actually say. Run the same prompt on both platforms and call your own phone, on the network your customers use.

Measure what the caller hears. The useful number is the gap between the caller finishing a sentence and the first audio of the reply, timed on a real phone line rather than in a browser demo. The latency guide explains how to time it and which parts of the path to separate. Then check the business side: do the outcome fields you need arrive in the webhook, and does the billed duration match your forecast once rounding is applied?